Tubular evaporative cooling system and steam cooling method

Abstract

The invention relates to a tubular evaporative cooling system and a steam cooling method. The steam cooling method comprises the steps that during the zero output heating operation of a low pressure cylinder of a steam turbine, a heating butterfly valve is closed, a steam regulating valve is opened, a steam inlet valve of a tubular evaporative cooler, a condensate water drain valve of the tubularevaporative cooler and an air pumping valve of the tubular evaporative cooler are opened, a steam inlet valve of an air cooled steam condenser, and a condensate water drain valve of the air cooled steam condenser and an air pumping valve of the air cooled steam condenser are closed; and all exhaust steam of a machine unit enters the tubular evaporative cooler for condensation, and condensate waterback flows to a main engine steam exhausting device. All the steam inlet valves of steam distributing pipes of the air cooled steam condenser are closed when the direct air cooling machine unit low pressure cylinder zero output heating operation in heating season, the air cooled steam condenser is isolated, all the exhaust steam of the machine unit enters the tubular evaporative cooling system and back flows to the main engine steam exhausting device after condensation, the freezing problem of heat exchange tube bundles of the air cooled steam condenser is effectively solved, and the freezingproblem of the air cooled steam condenser when the low pressure cylinder zero output heating operation of direct air cooling machine unit in winter is completely solved.

Description

technical field [0001] The invention belongs to the fields of heat supply, flexibility and safe operation of thermal power plants, and in particular relates to a tube-type evaporative cooling system and a steam cooling method. Background technique [0002] In order to improve the heating capacity of the unit and the deep peak-shaving capability of the heating unit, some units have undergone low-pressure cylinder zero-output heating transformation. The low-pressure cylinder zero-output heating technology transformation cost is low, the operation mode is flexible, and the thermal economy is good. Comprehensive Great advantage. [0003] The zero-output heating technology of the low-pressure cylinder breaks the original theory of the minimum cooling flow limit of the low-pressure cylinder of the steam turbine, cuts off the steam intake of the original low-pressure cylinder during the heating period, and only maintains a small amount of cooling steam by setting the bypass cooling...

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Problems solved by technology

[0004] Direct air-cooled combined heat and power units are widely used in the "Three North" regions of my country. After the direct air-cooled unit low-pressure cylinder has zero output transformation, the steam flow (heat load) entering the air-cooled condenser is theoretically very small, and it is extremely low under low temperature and low heat load conditions. It is easy to freeze the heat exchange tube bundle, which seriously affects the safe and reliable operation of the unit

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